Uv light From metal halides

[Cory]

Is there any data how much uva, uvb, and uvc a metal halide bulb would let through its protective glass?

 

[Doctorgori]

Is there any data how much uva, uvb, and uvc a metal halide bulb would let through its protective glass?

Sanjay did some spectral analysis on MH bulbs a while back ...
Here is the Article

may/might not answer your questions, I got sight issues and couldn’t read the charts

 

[Cory]

Same, im not sure how to read them to be honest.

Anyone know how much gets through compared to a uv sterilizer?

 

[taricha]

Same, im not sure how to read them to be honest.

Anyone know how much gets through compared to a uv sterilizer?

That part I can answer. It's zero, basically. The UV sterilizers use quartz because that can transmit the emission at 254 nanometers which is the Workhorse for a UV sterilizer. Glass transmits essentially zero of that wavelength.

 

[Cory]

That part I can answer. It's zero, basically. The UV sterilizers use quartz because that can transmit the emission at 254 nanometers which is the Workhorse for a UV sterilizer. Glass transmits essentially zero of that wavelength.

Well according to this quote i found, your right except for uva. The question, what do uva do to dinos?

Standard window glass, according to the International Ultraviolet Association, will allow UV-A to pass through while almost 100% of the UV-B and UV-C light is blocked. Therefore, some UV light will enter your home and potentially affect your skin. Some of these effects could include increased freckles and increased sensitivity to sunlight that could result in rashes such as photodermatitis.

 

[taricha]

Oh, I get your drift now. There is actually some interesting stuff along these lines about Dino response to photo oxidation and general light intensity stress.
It's most studied with ostreopsis, and they seem to have a hard time with it.

 

[Cory]

Oh, I get your drift now. There is actually some interesting stuff along these lines about Dino response to photo oxidation and general light intensity stress.
It's most studied with ostreopsis, and they seem to have a hard time with it.

They have a hard time with uva?

 

[taricha]

They have a hard time with uva?

They have a hard time with intense light generally.
In experimental conditions, they preferred less than 10% of natural sunlight. Also intense light seems to trigger behavior (mucus production and settling) that would allow them to attach to the shade of macroalgae or rocky substrate.
It would make sense if it were the most stressful fraction of the sunlight (violet/uv) that were responsible.

link

Morton et al. (1992) reported that O. cf. siamensis and O. heptagona isolated from the Florida Keys displayed maximal growth at approximately 200 μmol photons m–2 s–1 and did not grow rapidly at over 240 μmol photons m–2 s–1 (i.e., >10% full sun light). Scalco et al. (2012), analysing the growth performance of some Italian O. cf ovata strains, observed that this species grew better at relatively low photon flux density (50 instead of 200 μmol photons m–2 s–1). Yamaguchi et al. (2014) observed that Ostreopsis sp. from Japan grew proportionally when light intensity was increased from 49.5 to 199 μmol photons m–2 s–1, but its growth appeared to be inhibited slightly at >263 μmol photons m–2 s–1. Heil et al. (1993) observed that O. cf. siamensis cultured in spinner flasks would stay planktonic when light intensities are maintained low (25 μmol photons m–2 s–1), but would produce mucus and settle at the bottom at higher light intensities (75 μmol photons m–2 s–1). This has been interpreted as a protective measure to shade the cells. Therefore, in experimental conditions Ostreopsis sp. seems to suffer too high light intensities, therefore being exposed to potentially detrimental consequences of photodamaging.
In field conditions, there are only few data about the relationship between Ostreopsis abundances and light intensity, which, moreover, seem to disagree with the experimental evidences described above. A study carried out along several Italian coastal areas affected by Ostreopsis blooms showed that during the blooms, the values of light intensity at depth of Ostreopsis sampling were quite high, up to 1800 μmol photons m–2 s–1 (ISPRA, 2012). However, it is known that light availability amidst macroalgal vegetation is generally low (Raniello et al., 2004), and Ballantine et al. (1988) suggested that Ostreopsis cells can migrate to shaded areas of the algal host thallus to escape high light levels.

Other papers also discuss the decrease of ostreopsis blooms in the middle of summer and the resurgence in late summer early fall - and they speculate this might be another light intensity effect.

 

[jda]

MH lets in UV to about 350nm in small amounts compared to the rest of the output, but it varies from bulb to bulb. I can assure you that dinos can live in tanks with MH, though.

 

[Cory]

MH lets in UV to about 350nm in small amounts compared to the rest of the output, but it varies from bulb to bulb. I can assure you that dinos can live in tanks with MH, though.

Lol yeah thats what I was getting at. Uv sterilizer has taken control of the dinos in my tank. Trying to guage the major led/mh differences.

 

[A. grandis]

Lol yeah thats what I was getting at. Uv sterilizer has taken control of the dinos in my tank. Trying to guage the major led/mh differences.

Sterilizer lamps are designed totally different than the ones we use for corals.
To answer your "gauging question":